Wall structure and device for sealing thereof

ABSTRACT

A wall structure is described which contains joints sealed by a system operating in accordance with the rain screen principle. Adjacent panels have facing edge grooves and an air sealing member between the panels on the interior side thereof. A rain screen baffle, retained in only one of said grooves, spans the gap between the grooves with a flexible screen and cooperates with the air sealing member to create interiorly of the screen a pressure equalization chamber. Preferably there are also means to urge the screen into contact with outer sides of the two grooves.

United States Patent [191 Green 5] Nov. 18, 1975 WALL STRUCTURE ANDDEVICE FOR 3,813,838 6/1974 Brown et al. 52/396 SEALING THEREOF [75]Inventor: Robert Franklin Green, Morrison, f' Stltherland C010 AsszstantExammer-Carl D. Friedman Attorney, Agent, or Firm-Robert M. Krone; JamesW. [73] Assigneez Johns-Manville Corporation, McClain Denver, C010.

[22] Filed: Dec. 13, 1973 [57] ABSTRACT [21] Appl. No.1 424,266 A wallstructure is described which contains joints sealed by a systemoperating in accordance with the rain screen principle. Adjacent panelshave facing [52] US. Cl 52/396, 52/471 edg grooves and an air Sealingmember between the [51] lllt. Cl. E04B 1/68 panels on the interior Sidethereof A rain Screan f [58] Field of Search 52/471, 470, 396, 403 fie,retained in only one of Said grooves spans the gap between the grooveswith a flexible screen and coop- [56] References cued erates with theair sealing member to create interiorly UNITED STATES PATENTS of thescreen a pressure equalization chamber. Prefer- 3,205,629 9/1965 Rumleyet a1 52/396 ably th r are also means to urge the screen into 3,526,0719/l970 Watanabe 52/396 X contact with outer sides of the two grooves.3,691,708 9/1972 Firnkas r 52/403 X 3,742,669 7/1973 Mansfeld 52/396 6Claims, 7 Drawmg Figures U.S.;Patnt Nov. 18,1975 Sheet1of2 3,919,820

US. Patent Nov. 18,1975 Sheet20f2 3,919,820-

WALL STRUCTURE AND DEVICE FOR SEALING THEREOF BACKGROUND OF THEINVENTION The invention herein relates to a novel wall structure and adevice for sealing the joints therein. More particularly, it relates toa structure intended to serve as an exterior wall of a building, whereone side will be exposed to weather, to a device for sealing the jointsin the exterior wall against the weather, and to the sealing systemcommonly referred to as the rain screen principle.

Exterior walls of buildings are often constructed from a plurality ofindividual panels placed vertically or horizontally in edge-to-edgerelationship. At the joints where the edges of adjacent panels adjoin,gaps usually occur, occasionally because of less-than-perfect matchingof the adjoining edges or poor workmanship in construction. Morecommonly such gaps are deliberately left in the wall to permit expansionand contraction of the individual panels with changing temperatures.These gaps must be sealed by suitable weathertight means to prevent thewind, rain, snow and other inclement weather to which the exterior ofthe wall is exposed from penetrating to the interior side of the wall.Many types of sealing means have been proposed and- /or used at one timeor another. Among these is the system which operates on the well-knownrain screen principle. This principle is described in detail in AluminumCurtain Walls, volume 2, published in 1971 by the Architectural AluminumManufacturers Association of Chicago. In such a system an inner sealprovides the actual air seal. Exteriorly of this inner seal is a baffleextending between the two adjacent panels. Between the baffle and theseal is an air space known as a pressure equalization chamber. In theabsence of the equalization chamber, the moisture would easily pass thebaffle and penetrate the seal (or between the seal and the panel edge)because of the pressure differential between the interior and exteriorsides of the wall. With the equalization chamber formed by the presenceof the baffle, however, the pressure differential driving force formoisture penetration past the baffle is virtually eliminated. Thus onlyminor leakage of moisture past the barrier occurs, and the inner sealbecomes virtually weather-tight since it can be designed for optimum airsealing and does not have to simultaneously function as a water seal.

A number of different baffle designs have been proposed. Some, such ascertain of those shown in the aforecited Aluminum Curtain Walls article,are suitable only for sealing horizontal openings. Others, such as rigidmetal strips, as satisfactory only for vertical openings. Further, manysuffer from the disadvantage that they can be emplaced only aftererection of the wall, and necessitate complicated assembly procedures.Thus, for instance, rigid metal strips cannot be placed in wall groovesin the adjacent panel edges other than from the ends of the assembledpanels. Thus, each long metal strip must be inserted from the end of thepanels and run through the entire length of the panels. This is a verytime-consuming process, and often results in serious bending or kinkingof the long thin strips. Also, since the rigid metal strips fit onlyloosely into the wall grooves, they cannot be emplaced when only onepanel 2 is erected; rather both panels must be in place to form anenclosed groove to hold the strip.

Complex assembly requirements for use on the job site are expensive,time-consuming and lead to many 5 improperly constructed walls which donot adequately seal against weather. It would therefore be verydesirable to have a rain screen baffle which could be incorporated intoa wall panel by the factory which produced the panel. On the job sitethe panel could then be erected and the baffle would simultaneously beplaced without any separate effort by the workmen. Also, by beingcarefully incorporated under factory rather than field conditions, theproportion of misaligned or otherwise faulty baffles would besubstantially reduced.

Alternatively, where field assembly is planned, it would be desirable tohave a baffle which could be easily installed. It would be especiallydesirable to have a baffle which could be attached to an emplaced paneland be retained in place solely by that panel. In this way verticalbaffles could be put up on the edge of a vertical panel prior to theemplacement of the adjacent panels.

IT is therefore an object of this invention to provide a novel wallstructure in which the joints between adjacent panels are easily andsecurely sealed and baffled during construction.

It is also an object of this invention to define a baffle device whichmay be easily handled, readily installed, and which will remain in placewithout supplementary support.

It is further an object of this invention to provide a baffle devicewhich maintains continuous and positive operation under all normalconditions of expansion and contraction of the wall structure.

It is further an object of this invention to provide a baffle devicewhich may be attached to a panel on the job site or at the factory.

BRIEF SUMMARY OF THE INVENTION The invention herein includes a wallstructure suitable for use in weatherexposed locations which comprises:a first wall panel a second wall panel in edge-toedge adjacentrelationship to the first wall panel, substantially coplanar therewith,and spaced therefrom, whereby a gap is formed between the facing edgesof the panels; each of the panels having a longitudinal groove in theedge adjacent to the other panel, the two grooves thereby being infacing edges and substantially opposed to each other; an air sealingmember attached to the interior portion of the panels and spanning thegap therebetween; and a baffle member having means securing the bafflemember in one of the edge grooves, and a flexible screen extendingacross the gap between the panels exteriorly of said air sealing memberwhereby a pressure equalization chamber is formed between said airsealing member and said screen. Preferably the structure also includesmeans associated with the baffle member to urge the flexible screen intocontact with the exterior of each of the two grooves.

The invention also comprises a flexible baffle device for use betweentwo adjoining sections of wall, wherein the facing edges of theadjoining wall sections each contain a longitudinal groove, whichcomprises: means to secure the baffle device in one of the grooves and aflexible screen which extends into the facing groove. The devicepreferably also contains means to urge the screen into contact with theexterior sides of both grooves.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective sectional viewof a small portion of a wall structure, showing the adjoining edges oftwo adjacent wall panels and illustrating the use of the sealing systemof this invention to seal the gap between the adjacent sections.

FIG. 2 is a sectional plan view showing the joint between two adjacentwall sections and the sealing system a baffle device of the presentinvention in place therebetween. The Figure shows in solid lines thesealing configuration with the wall panels in their contracted state;i.e., with the gap between them at its widest, and in phantom lines theconfiguration with the wall panels in their expanded state; i.e., withthe gap between them compressed to its smallest width.

FIG. 3 is similar to FIG. 2, and illustrates another embodiment of thebaffle device of the present invention.

FIGS. 4a and 4b illustrate in section still another embodiment of thebaffle device and its means of emplacement and retention.

FIG. 5 illustrates in section still another embodiment of the baffledevice of this invention and its method of retention.

FIG. 6 illustrates in section yet another structure of this invention,this being an embodiment in which the screen and the retention means areseparate apparatus rather than being merged into a single unit, as arethe embodiments in FIGS. 2 and 3.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS tion of the wallstructure which is actually exposed to the elements or which is thenearest to the exposed surface of two or more comparable portions. InFIGS. 1-3 and 6 of the drawings, the weather side is designated by thelarge arrows. In other words, the inclement weather is directed againstthe wall structure from the direction indicated by the arrows.

The wall structure of this invention (generally designated 2) comprisesseveral principal parts: a first wall panel 4, a second wall panel 6, abaffle 8, an inner seal 9, and a pressure equalization chamber 11 (whichis formed by the boundary surfaces of the other parts). The wall panelsand grooves illustrated in the Figures are shown in verticalconfiguration. However, it will be understood that the principle andoperation of the system of this invention are the same for a horizontalconfiguration, and all comments herein are equally applicable thereto.The wall panels 4 and 6 contain in their adjacent edges respectivelygrooves and 12. Ordinarily, each groove will extend the full length ofthe edge of the panel. The fact that the grooves do not extend theentire length or height of the panel does not affect the presentinvention, however. Conveniently, both of the grooves will have similaror identical crosssectional shapes. Such a configuration is preferredfor it permits the baffle device 8 of this invention to be inserted intoeither groove at the choice of the workman. Where the grooves are ofsubstantially different crosssectional shapes, it will usually be foundthat the base 4 portion of a given baffle will fit satisfactorily onlyinto one of the grooves.

The wall panels 4 and 6 4ay conveniently be 6f any material suitable forexterior building use and having an edge a thickness sufficient toincorporate the grooves 10 and 12 therein. Wood, exterior grade sheetrock, concrete and the like are all suitable. Also suitable are wallstructures wherein the edges are sufficient thickness although the panelfacings may be of thin sheet material. Thus, sheet metal or plasticpanels with wooden edges, as shown in FIG. 3, and similar structures arealso suitable. A preferred type of panel is made of extrudedasbestos-cement. Extrusion offers the advantage of the ability to formthe edge grooves at the time that the panel itself is formed, thuseliminating any necessity for a separate groove forming step. Typical ofthe extruded asbestos-cement panels preferably used in the wallstructure of this invention are those marketed under the trademarksCORSPAN and FACESPAN by the Johns-Manville Corporation.

On the interior side of the wall structure 2, inwardly of the opposinggrooves 10 and 12, is air sealing device 9. As shown herein, this is anelastomeric strip of material running the length of the gap between thepanels, and being joined at all points to the opposite edge faces 13 and15 of wall panels 4 and 6. Any resilient elastomeric material will servefor sealing device 9. Since a small amount of mositure ordinarily doespass beyond baffle 8, air sealing device 9 should be of water resistantmaterial. It does not act as a water seal, of course. It may be joinedto faces 13 and 15 by conventional cements or adhesives.

An important component of the wall structure of the present invention isthe baffle device 8. This comprises means to secure the device in agroove such as 10, and a screen to span the gap between panels 4 andextend into the facing groove, such as 12, to form pressure equalizationchamber 11 outwardly of air sealing device 9.

Two preferred embodiments are shown in FIGS. 2 and 3, with that in FIG.2 being the more preferred. In these embodiments, the retention meansused to secure the baffle 8 in the groove (in this case 10) comprisesresilient base 14. The flexible screen which is also part of theone-piece unit is designated 16. The base 14 is usually relatively rigidas compared to the screen 16. In the embodiment shown in FIG. 2, thebase portion of 14 must be sufficiently rigid to be retained in thegroove 10 during shipping of the panel, assembly of the wall and inservice thereafter. However, it must also be sufficiently deformable andresilient that it can be inserted into the groove 10 past retainingconstrictions 18 and 20 and thereafter expand to fill the back portionof groove 10. A number of materials will serve satisfactorily for such abase section, having the appropriate combination of deformability,resilience and'stiffness. Typical of these are many of the natural andsynthetic rubbers as well as a variety of other elastomeric materials.

Alternatively, as shown in FIG. 3, the base portion may be made of arelatively soft material (such as an elastomer of appropriateproperties) inserted into' place in groove 10 and then filled with arigid stiffening material 22 such as a foamed plastic to maintain theshape of the base section. In another embodiment, shown in FIG. 5,groove 10 has no restraining constrictions of the type used for afriction fit of the base section. Rather the base portion is insertedinto a straightsided groove and then a cover plate 17 'i s'attached" tothe end of wall section 4 as by-bolt '19 to holdthe'baffle 8 inposition. Because of the added components and extra operations requiredfor assembly, these embodiments are not preferred. In the embodiment ofFIGS. 1 and 2, the groove 10 is of an hour glass? shape and the baffle 8is held in the groove by force fit, with the base 14 being deformedsufficiently to be inserted past the ridges and 18 and then resilientlyself-expanding in the inner portion of groove 10 in a trapezoidal shapeto completely fill the groove and maintain a frictional contact with thesurfaces of the groove. Reference is here made (for brevity) only togroove 10. It will be of course understood that where grooves 10 and 12are essentially alike, the comments herein to groove 10 apply equally togroove 12, and vice versa in the discussion of the screen 16. The choiceof assembly positions is simply one of convenience to the installer.

In another embodiment, of FIGS. 4a and 4b, groove 10 is usuallystraight, but may have a slight taper. Base 14 is serrated on its outersurface, having teeth or fins 21 which project to a width greater thanthe width of groove 10. In use the baffle 8 is forced into groove 10 andteeth 21 compress to lock into the groove.

In still another embodiment utilizing two separate pieces for the screenand the retention means, screen 16 is a flat flexible strip of materialextending into grooves 10 and 12. It is held in place in groove 10 byspring 23, shown here as a curved strip of metal or rubber. Other typesof springs, such as coil, springs, can also be used.

The screen 16 is a single strip of flexible material which is resistantto the various weather phenomenon to be encountered. The material musthave sufficient flexibility to bend readily and change shape (asdesignated at 16 and 16 in FIGS. 2 and 3) with the expansion andcontraction of the wall. It must, however, have sufficient stiffness toresist being folded back by winds that blow against the wall. Suitablematerials are many elastomers or flexible metals, although the latterare less preferred because of their cost and their susceptibility tobeing bent or dented during handling. The screen 16 extends completelyacross gap 25 and into both grooves 10 and 12. Preferably screen 16 isof sufficient breadth to extend completely across the breadth of grooves10 and 12 to approach or contact the back surface of groove 12 asindicated at 26. An excess of material may be used to give screen 16 aconvex shape to bias screen 16 into contact with the outer surfaces ofgrooves 10 and 12. In other words, the breadth of screen 16 shouldpreferably be somewhat greater than the distance from the point ofconnection with base portion 14 to contact with the back wall of groove12 when the wall is in its most contracted position; i.e., when the gapbetween adjacent sections 4 and 6 is at its greatest. Preferably, theend or tip 28 of leg section 16 will be rounded in cross-section, e.g.,bulbous or hooked as shown respectively in FIGS. 2 and 3. This aids thetip of screen 16 in sliding along the back surface of groove 12 andprevents it from being snagged on a surface irregularity of the groove.When the wall is in its most fully expanded condition, i.e., when thegap is at its smallest, flexible screen 16 is curved down to theposition shown as 16 in FIGS. 2 and 3. In this configuration, contactwith the outer walls of grooves 10 and 12 is possible in allintermediate positions between the maximum contraction and expansion.

In the configuration shown in FIG. 3 the screen "16 extends from themiddle of the base 14. This is less preferred butmay be used whereexpected wind velocities are moderate. r I

As shown in FIGS. 2 and 6, the tip of screen 16 need not touch the backend of groove 12, as long as the screen 16 extends substantially intothe groove and has sufficient resilience not to be unduly bent back bythe wind to close off chamber 11. It will also be noted that in someconfigurations, such as that shown in FIG. 46, the screen portion ingroove 10 is at least in part coextensive with a portion of base 14, asindicated at 27.

The means urging screen 16 into contact simultaneously with the exteriorsides of grooves 10 and 12, as illustrated in FIGS. 1 and 2 isordinarily and preferably the resiliency in flexible screen 16, whichmakes screen 12 try to assume a straight configuration, thus urging thescreen outwardly. Alternatively, a flexed metal backing, such as metalstrips, or similar strips embedded in the screen 16, or the like may beused.

The baffle 8 extends the full length of the gap between panel 4 and 6.Throughout its length screen 16 is in contact with the inner surface ofgroove 10 and the outer surface of groove 12. Contact need not becontinuous at all times over the entire length, but will be generallymaintained.

Assembly is readily understood from the drawings. The baffle 8 isinserted into groove 10 and held by the retention means. This can beaccomplished in the field, either with the panel erected or in a storagearea, or in the factory where the panel is produced.

What is claimed is:

1. A wall structure incorporating the rain screen principle and suitablefor use in weather exposed locations, which comprises:

a first wall panel;

a second wall panel in edge-toedge adjacent relationship to said firstwall panel, substantially coplanar therewith, and spaced slightlytherefrom, whereby a gap having an outward portion and an inward portionis formed between the facing edges of said panels;

each of said panels having a longitudinal groove in the edge adjacent tothe other panel, the two grooves thereby being in facing edges,substantially opposed to each other, and dividing said gap into 7 itsrespective outward and inward portions;

an air sealing member attached to the inner portion of each of theopposed edges inwardly of the grooves therein, and spanning the inwardportion of said gap therebetween;

a baffle device comprising retention means for securing said baffledevice in one of said grooves and a flexible screen spanning said gapand extending into the other of said grooves; said baffle device alsocomprising means for urging said flexible screen into contact with theouter sides of both of said grooves; and no portion of said baffledevice substantially extending into that portion of said gap which liesoutwardly of said grooves; and

said flexible screen and air sealing member cooperating with saidgrooves to form a pressure equalization chamber, whereby a substantiallyweathertight seal is created across said gap and the penetration ofmoisture to the interior of said wall structure is prevented.

8 said baffle device which is serrated and the serrations serve toretain said baffle device in said groove.

5. The wall structure of claim 1 wherein said baffle device is retainedin said groove by a rigid core filing the hollow base of said baffledevice.

6. The wall structure of claim 1 wherein said urging means comprises theresilience of said flexible screen. l

1. A wall structure incorporating the rain screen principle and suitablefor use in weather exposed locations, which comprises: a first wallpanel; a second wall panel in edge-to-edge adjacent relationship to saidfirst wall panel, substantially coplanar therewith, and spaced slightlytherefrom, whereby a gap having an outward portion and an inward portionis formed between the facing edges of said panels; each of said panelshaving a longitudinal groove in the edge adjacent to the other panel,the two grooves thereby being in facing edges, substantially opposed toeach other, and dividing said gap into its respective outward and inwardportions; an air sealing member attached to the inner portion of each ofthe opposed edges inwardly of the grooves therein, and spanning theinward portion of said gap therebetween; a baffle device comprisingretention means for securing said baffle device in one of said groovesand a flexible screen spanning said gap and extending into the other ofsaid grooves; said baffle device also comprising means for urging saidflexible screen into contact with the outer sides of both of saidgrooves; and no portion of said baffle device substantially extendinginto that portion of said gap which lies outwardly of said grooves; andsaid flexible screen and air sealing member cooperating with saidgrooves to form a pressure equalization chamber, whereby a substantiallyweathertight seal is created across said gap and the penetration ofmoisture to the interior of said wall structure is prevented.
 2. Thewall structure of claim 1 wherein the two grooves have substantiallyidentical cross-sectional shapes.
 3. The wall structure of claim 1wherein the groove in which said baffle device is retained has aconstriction in its cross-section, and the retention means of saidbaffle device is retained behind said constriction.
 4. The wallstructure of claim 1 wherein said retention means comprises a portion ofthe outer surface of said baffle device which is serrated and theserrations serve to retain said baffle device in said groove.
 5. Thewall structure of claim 1 wherein said baffle device is retained in saidgroove by a rigid core filing the hollow base of said baffle device. 6.The wall structure of claim 1 wherein said urging means comprises theresilience of said flexible screen.